The invention relates to a device for selection and adjustment of the reclining angle of folding seats and armchairs, and similar structures.
Conventional folding chairs consist in a seat and a backrest which are hinged together and carried by two pairs of crossed legs pivotably associated one with another at each side of the seat, the front legs connecting with the uprights of the backrest; the top ends of the legs are attached to the seat in such a way as enables their movement in relation thereto.
Chairs of this kind are able to assume a number of configurations within two limit positions. In the first such limit position, the seat and backrest lie substantially at right angles to one another, whilst in the second, the chair assumes a reclining profile in which the legs are at minimum height, spread out as wide as possible with their top ends near to the edge of the seat.
The various positions are obtained by locating pins, associated with the top ends of one pair of legs, in one of a relative set of pairs of notches issuing from straight slots formed in each side of the seat.
The slots may be formed either in the rear or in the front of the seat. In either instance, the user adjusts the angle of the backrest by rotating the seat upwards; this frees the pin from the notch currently occupied and allows it to slide along the slot until engaging a further notch such as will give the desired angle.
Where the adjustment slots are located at the rear of the seat, it can happen that the occupant of the chair perches on the front edge of the seat and causes it to rotate accidentally, with the result that the pins escape from the notches currently engaged; the chair drops suddenly and at a single stroke into the reclining position, and the user's fingers can become trapped between the seat and the legs.
Similarly, with the slots located at the front, it may happen that, in gripping the front edge to the end of pulling the seat further forward, the user inadvertently rotates the seat upward, freeing the pins from the notches and producing the same result as described above.
Accordingly, the object of the invention is to overcome the drawbacks aforementioned.